Multiple race accounting is already part of the new standard government statistics, but demographers still face the challenge of how to model and forecast the growth of multiracial populations. This research proposes simple matrix models for studying multiracial population dynamics. These models show the wide range of demographic futures that the United States could be facing and provide a means for assessing the implications of existing trends. Growth in the multiracial population could have consequences for race-based public policies, the measurement of racial disparities in health and socioeconomic status, and also for the subjective meaning and social importance of race in the United States.